WASHINGTON — Rep. John J. Duncan Jr. thought he was probably ending his political career when he pressed the “no” button and voted against going to war with Iraq.

Sixteen years later, the Knoxville Republican will leave Congress on his own terms.

Duncan, one of only seven Republicans to vote against the Iraq War and the only one of those seven still in office, announced last week that he will not seek re-election next year.

The soft-spoken, mild-mannered Tennessean’s decision to defy his own party, and the wishes of many of his constituents, and oppose what he considered an unnecessary conflict was the defining moment of his nearly 30-year career in politics. Outside of his home state, it’s the thing he will be most remembered for when he leaves office.

To this day, Duncan is convinced he made the right call, even though he suffered years of fallout over his vote.

“What I’ve noticed over the years is so many people who haven’t served in the military, they seem to have this real strong desire to prove how tough they are and prove their patriotism,” Duncan said. “I just thought back then, and I think now, that we shouldn’t be so eager to go to war.

“So many people in Washington want to be Winston Churchills, and they seem to want to turn any world leader they possibly can into a new Hitler,” he said. “Most of the time that’s not really true.”

Duncan’s skepticism about the war was rooted to some degree in the first Persian Gulf War a decade earlier. He had supported that war because he and other members of Congress had been told that Iraqi leader Saddam Hussein was a dangerous threat to the United States. But not long after the war started, he started to believe the threat had been exaggerated when Hussein’s elite troops began surrendering in droves.

Duncan had the same doubts when then-President George W. Bush began the march toward a second war with Iraq in 2002.

The White House knew Duncan was on the fence, so Bush’s top advisers called him and two other undecided Republicans into a meeting.

In a secure, windowless room in the White House basement, national security adviser Condoleezza Rice, CIA Director George Tenet and Tenet’s deputy director, John McLaughlin, laid out the case for war. They showed the wavering lawmakers aerial photos of buildings and trucks in the desert, argued that most Iranians hated Hussein and would be glad to see him go, and insisted war was inevitable to preserve national security.

Duncan left that briefing still not convinced that Iraq posed an imminent threat.

A month later, the House voted 296-133 to go to war. Early the next morning, the Senate approved the war resolution on a 77-23 vote. Only seven Republicans — six in the House, one in the Senate — voted against the war.

Six of those seven would go on to lose their races for re-election or would eventually retire from Congress. Duncan, though, remained in office and never drew a serious challenger.

He did, however, face repercussions from his vote. Constituents would stop him on the street and tell him he’d disappointed them. A Baptist preacher withdrew an invitation for him to deliver a Sunday lay sermon after one of the deacons threatened to leave the church if the congressman was allowed to speak.

“For three or four years, it was clearly the most unpopular vote I had ever cast,” Duncan said.

Public opinion on the war — and on Duncan’s vote — gradually shifted as the conflict dragged on.“It slowly became the most popular vote I have ever cast,” Duncan said. “I think to this day, it still is.”

Duncan is a strong supporter of President Donald Trump, who threatened on Tuesday to respond to North Korea "with fire and fury like the world has never seen” amid reports that country has produced a miniaturized nuclear warhead that can fit inside its missiles.

Duncan said he considers North Korea a threat and believes the U.S. should take that threat seriously.

But, “I also think there are better ways to handle it short of making pre-emptive strikes,” he said. “And we should especially consider the views of our allies in South Korea, because they are the ones most directly affected by it.”

Regardless, Duncan said he continues to believe that the U.S. needs a more “humble” foreign policy.

“We’ve created a lot of animosity around the world because we’ve butted into a lot of things we shouldn’t have,” he said. “Obviously, though, on the Republican side it is more popular to be hawkish. I’m a little out of step with the party in that respect.”